Device for removing liquids from gas wells



Jan. 30, 1968 B. J. SHIRLEY 3,366,074

DEVICE FOR REMOVING LIQUIDS FROM GAS-WELLS Filed July 8, 1966 2Sheets-Sheet 1 ITOPA/FKS Jan. 30, 1968 B. J. SHIRLEY DEVICE FOR REMOVINGLIQUIDS FROM GAS WELLS 2 Sheets-Sheet 2 Filed July 8, 1966 INVENTOR. 9 pI 6/1.; /E' 4/0 SH/ LEY United States Patent 3,366,074 DEVICE FORREMOVING LIQUIDS FROM GAS WELLS Billie J. Shirley, P.O. Box 33,Woodward, Okla. 73801 Filed July 8, 1966, Ser. No. 563,915 12 Claims.(Cl. 103232) This invention relates to oil and gas well tools, and moreparticularly, to well tools used in the removal of liquids from thebores of predominantly gas wells by the use of gas pressure.

A great number of so-called intermitter or differential pressureactuated devices have been proposed for use in removing substantiallyall of the liquid from the annulus of a well into which connate liquids,such as oil and water, have entered and built up a sufiicienthydrostatic head to prevent flow of gas from the well into theproduction tubing. All of these tools have as their object, thereduction of the water or oil level in the gas Well to the point wherethe gas can be produced with such removal being accomplished withoutsubstantial loss of gas pressure or undesirably large quantities of gas.Many of the intermitter devices which have heretofore been proposed andwhich operate on the basis of differential pressure have beencomplicated in operating principles and expensive to manufacture. Othershave functioned imperfectly and have been restricted in their usefulnessto certain types of wells and prevailing conditions. One of theundesirable characteristics which has frequently been encountered insome of the devices previously used is that certain valve elements usedin the device and operated by differential pressure do not seat smoothlyand easily, but instead, tend to bounce to reverberate on the seat dueto the sudden impact of closing or opening, and such chattering andvibration soon destroys the effectiveness of the tool and requires itsrepair or replacement.

The present invention provides a down hole tool for removing liquidsfrom a gas well in an efiicient and predictable manner. The tool isoperated by differential pressure in accordance with general principlesheretofore well known, but achieves improved performance, and issubstantially simpler in its construction and more economical tomanufacture than tools of this general type which have been heretoforeprovided. Broadly described, the present invention comprises anelongated tubular element having first and second ends and a boreextending therethrough, the tubular element further having a capillaryorifice extending through the wall to the bore and preferably positionedadjacent one end of the tubular element. An annular seat is located inthe bore of the elongated tubular element, and is spaced from thecapillary orifice toward the other end of the tubular element. Theopening through the seat is aligned with the bore of the tubularelement. At least one opening of substantially larger size than thecapillary orifice is provided through the wall of the tubular elementwith such openings being located on the opposite side of the seat fromthe capillary orifice.

A valve closure member which is dimensioned to mate with the seat toprevent fluid flow therethrough is provided in the bore of the tubularelement and is positioned on the opposite side of the seat from thecapillary orifice. An elongated valve stem is used for interconnectingthe valve closure member with a piston element which is secured to theopposite end of the elongated valve stem from the valve closure memberand is slidingly positioned in the bore of the tubular element. Plugmeans is provided for obstructing and sealing the bore through thetubular element, and sealingly and slidingly engages the elongated valvestem so that the stem can be reciprocated through this plug means.Positive stop means is provided 3,366,974 Patented Jan. 30, 1968 in thetool for limiting the movement of the piston element, the valve stem andthe valve closure member away from the seat. An adjustable control meansis located externally of the tubular element and cooperates with aportion of the piston element which projects from one end of the tubularelement for resiliently biasing the piston element against the positivestop means with a predetermined force. Finally, by-pass conduit means isprovided and communicates with the bore at a point in the tubular memberwhich is on the same side of the seat asthe capillary orifice. Theby-pass conduit means extends around the plug means to a point in thebore of the tubular member which is between the piston element and theplug means.

In a preferred embodiment of the invention, the tool is further providedwith pneumo-hydraulic cushioning means which functions to prevent themoving parts within the bore of the tubular element from chattering asthey engage the positive stop means and the valve seat during differentphases of the operation of the tool.

The number of moving parts which are provided in the tool of the presentinvention is relatively small as compared with a number of such elementswhich have been utilized in many previous types of tool. Moreover, theconstruction which is employed assures minimization of opportunity formalfunctioning to occur so that the tool is characterized in having along and trouble-free operating life. The liquid removing device of theinvention will effectively remove substantially all of the liquid whichhas accumulated in the annulus of the well bore and is preventingproduction of gas by the well. The gas pressure in the well is notreduced to any significant degree when using the device, and very littleof the gas is produced during the operation of the tool for removingliquid from the well bore.

From the foregoing description of the invention, it will be apparentthat a major object of the invention is to provide an improvedintermitter or pressure differential actuated tool for removing liquidfrom a well.

A more specific object of the invention is to provide a tool forremoving water or oil from a gas well so that the well may produce moreefiiciently, which tool does not chatter or vibrate excessively duringits cycle of operation.

An additional object of the invention is to provide a relatively simple,compact tool which can be placed on the end of conventional gas wellproduction tubing strings and used to reduce a liquid head accumulatedin the annulus of the well and thus permit gas to be more efficientlyproduced therefrom.

An additional object of the invention is to provide a mechanicallyrugged, yet relatively simply constructed well tool which ischaracterized in having a long and trouble-free operating life, andwhich can be employed for removing liquids from gas wells.

In addition to the foregoing described objects and advantages, a numberof additional objects and advantages characterize the present inventionand will become apparent as the following detailed description of theinvention is read in conjunction with the accompanying drawings whichillustrate the invention.

In the drawings:

FIGURE 1 is a vertical sectional view through a typical gas well anddepicting the present invention secured to the lower end of a string ofproduction tubing.

FIGURE 2 is a vertical sectional view through the center of the liquidremoving tool of the present invention.

FIGURE 3 is a sectional View taken along line 33 of FIGURE 2.

FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 2.

FIGURE 5 is a sectional view taken along line S5 of FIGURE 2.

FIGURE 6 is a horizontal sectional view taken along line 66 of FIGURE 2.

FIGURE 7 is a horizontal sectional view taken along line 77 of FIGURE 2.

Referring initially to FIGURE 1 of the drawings, the environment inwhich the tool of the invention is typically used is illustrated, andincludes a well casing 10 which extends downwardly into the earth 12 andterminates in an open hole completion providing an uucascd portion ofthe hole 14 at the lower end of the well. The casing 10 extends to awellhead 16 and is provided with an outlet pipe 20 through which gasproduced from a producing formation 22 may be conducted to a reservoiror point of use. A production tubing string 24 is extended downwardlyinto the well concentrically in the casing 10 and terminates in theuncased portion of the well adjacent the lower end thereof. An outletpipe 26 is provided for conducting to an open tank or to a gas liquidseparator fluids forced to the surface through the production tubing 24.Secured to the lower end of the production tubing 24 by a typical boxand pin connection 28 is the well tool of the present invention,designated generally by reference numeral 30 and illustrated in greaterdetail in FIGURES 2-7.

In referring to FIGURE 2, it will be noted that the tool may bedescribed as a three sectioned hollow body, or may be differentlycharacterized as an elongated tubular element. Adhering for the momentto the former description, the tool includes an upper body section 32, acentral body section 34, and a lower body section 36. Each of the bodysections is provided with a bore extending therethrough with the boresof the three body sections coaxially aligned to form the elongatedtubular element of the tool. The upper body section 32 carries anexternally threaded tapered neck portion 38 which forms the pin of atypical box and pin connection.

Immediately below the threaded tapered neck portion 38 of the upper bodysection 32, a capillary orifice 40 is provided and extends through thewall of the elongated tubular element of the tool and communicates withthe bore which extends through the upper body section 32. A secondorifice 42 substantially larger than the capillary orifice 40 isprovided through the wall of the tool on the opposite side of the borefrom the capillary orifice for a purpose hereinafter described. Acounterbore 44 is formed in the lower end of the upper body section 32to define a downwardly facing shoulder 46. A seat 48 carrying a sealingO-ring 50 bears against the shoulder 46 and is provided with a central,frusto conically tapered aperture 52.

A hollow cage 54 is connected to the seat 52 and is characterized inhaving a plurality of circumferentially spaced, relatively large ports56 therein. The ports 56 are much larger than the capillary orifice 40and are placed in communication with the exterior of the tool through alarge opening 58 formed in the wall of the tool. It will be noticed thatthe cage is of smaller diameter than the diameter of the counterbore 44so that an annular spac exists between the outer periphery of the cage54 and the interior wall of the upper body section 32. The cage 54threadedly engages plug means 60 which includes an elongated, externallythreaded tubular body 62 having a relatively large bore 64 formed in theupper end thereof adjacent the cage 54 and an intermediate diameter,first counterbore 66 and a relatively small diameter second counterbore68. The lower face of the plug means 60 is recessed as indicated byreference numeral 70 and receives an annular packing element 72 andsuitable retaining rings 74.

Positioned within the first counterbore 66 of the plug means 60 is atubular sleeve 76 which is preferably constructed of a relatively highdensity, low coefficient of friction synthetic resin, such as nylon orTeflon. The sleeve 76 is provided with a radially outwardly extendingannular flange 78 adjacent its upper end with such flange extending tothe defining walls of the counterbore 66. Be-

neath the flange 78 in the annular space between the shank portion ofthe sleeve 76 and the wall of the counterbore 66 are a plurality ofpacking rings 80 which are placed in compression by the flange 78 whenthe sleev 76 is fully seated as hereinafter described. An annularretaining ring 82 bears against the flange 78 and is biased thereagainstin a resilient manner by a compression spring 84 which extends betweenthe retaining ring 82 and the lower end of the valve cage 54 which isthreaded into the upper end of the plug means 60.

The tubular body 62 of the plug means 60 is provided with an annulargroove 85 adjacent its upper end and with a sealing ring 86 which ispositioned in the annular groove and bears against the internal wall ofthe upper body section 32. Below the annular groove 84 and sealing ring86, the external peripheral surface of the body 62 is threaded andengages the internally threaded lower end of the upper body section 32.The lower end of the tubular body 62 of the plug means 60 is alsothreaded, and threadedly engages the upper end of the central bodysection 34 of the tool. A pair of sealing rings 90 and 92 are providedin accommodating annular grooves intermediate the threaded portions ofthe body 62 which engage the upper body section 32 and the central bodysection 34 of the tool so as to form a seal connection between thesebody sections when the plug means 60 is used for interlocking them inthe manner illustrated in FIGURE 2.

An elongated valve stem 94 extends upwardly in the bore through theelongated tubular element of the tool, passing through the packing 70,the sleeve 76 and the compression spring 84 positioned in the bore 64.The valve stem 94 has its upper end extended through a central aperture95 in the lower end of the valve cage 54. A valve closure member 96 isformed integrally with or secured to the upper end of the valve stem 94,and is dimensioned to engage the valve seat 48 as it moves into thefrusto-conical tapered aperture 52. The lower end of the valve stem 94carries a plurality of annular ribs 98 which project into, or interlockwith, mating grooves 100 formed in a connecting collar 102. Theinterlock formed between the ribs 98 and grooves 100 is relatively looseto provide a flexible connection. The grooves 100 of the connectingcollar 102 also interlock loosely with annular ribs 104 provided on anupwardly projecting piston neck 106. It will be noted that a space orgap is provided between the upper end of the piston neck 106 and thelower end of the valve stem 94, again for the purpose of providing aflexible, universal movement connection between the piston neck and thevalve stem.

Approximately midway of the length of the central body section 34, anaperture 107 extends through the body section to place the bore of thetool in communication with an elongated, small diameter tubing 109 whichis also in communication with orifice 42 in the upper body section 32.The purpose of this arrangement will be hereinafter explained.

The piston neck 106 projects from the upper end of a piston cap element108 which is screwed into and closes the upper end of an elongatedhollow piston body 110 which extends downwardly in the bore of thecentral body section 34 of the tool. An annular sealing ring 112 iscarried in a groove 114 formed around the outer periphery of the hollowpiston body 110 and forms a sliding seal between the piston body and theinternal wall of the central body section 34. It will be noted inexamining FIGURE 2, and specifically, the configuration of the pistonbody 110, that an annuar downwardly facing shoulder is formed on thepiston body and functions as a positive stop element in a mannerhereinafter described. The hollow interior of the piston body 110extends to a point near the lower end of the piston body. A relativelysmall diameter first conduit 116 extends from outside the piston body110 through the wall thereof to a point adjacent the lower end of thehollow interior of the piston body. An air bleed tube 118 also extendsfrom the exterior of the piston body 110 into the hollow interiorthereof with the air bleedtube terminating at a point spaced verticallyabove the lower end of the first conduit 116.

The lower body section 36 of the tool is threadedly connected to thelower end of the central body section 34 and a suitable sealing ring 122is provided to assure sealing engagement between these two sections ofthe tool. The lower body section 36, in addition to a relatively large,threaded bore 124 formed in the upper end thereof for receiving thethreaded lower end of the central body section 34, also has a relativelysmaller diameter counterbore 126 formed in the lower end thereof whichmore closely surrounds, but yet is slightly spaced from, the externalperiphery of the piston body 110. By this construction, an upwardlyfacing shoulder 128 is formed in the lower body section 36, and thisshoulder cooperates with the downwardly facing shoulder 120 carried bythe piston body 110 to limit movement of the piston in the bore of thetool during its operation as hereinafter described. The extreme lowerend of the piston body 110 is externally threaded and receives anadjusting nut 130 which can be threaded on the lower end of the pistonbody to any desired axial location therealong. A compression spring 132is interposed between the adjusting nut 130 and an annular, springreceiving detent 134 formed on the lower end of the lower body section36.

Operation In use, the tool 30 of the invention is secured to the lowerend of a production tubing string 24 by a conventional box and pinconnection in which the threaded neck portion 38 of the upper bodysection 32 is threaded into the lower end of the tubing string. The tool36 has been assembled with the body sections 32, 34 and 36 threadedlyengaged in the manner illustrated in FIGURE 2. As the tubing string isinitially lowered in the well, the resilient biasing action of thecompression spring 132 extends the piston body 110 from the lower bodysection 36 so that the downwardly facing shoulder 120 bears against theupwardly facing shoulder 128. It should be pointed out that the spring132 is selected, and the adjusting nut 130 is set in a selected axialposition on the lower end of the piston body 110, so that the springexerts a predetermined downward bias on the piston body. Thus, forexample, let it be assumed that the spring exerts a downward force onthe piston body of 300 p.s.i.g.

As the tubing string moves downwardly in the well bore and approachesthe position depicted in FIGURE 1, the bottom hole pressure exertedthrough the liquid located in the well acts upwardly on the lower end ofthe piston body 110 and against the total cross sectional area of thepiston which is sealed against the internal wall of the bore of thecentral body section 34. This upwardly acting pressure which, say, is800 p.s.i.g., overcomes the downward bias of the compression spring 132and thus causes the piston body to slide upwardly in the central andlower body sections 34 and 36, respectively. It should :be noted that,even though prior to the upward movement of the piston body 110, theliquid standing in the well bore can enter the tool through the largeopening 56, this liquid is isolated from the piston body in the plugmeans 60. The liquid which enters the opening 58 thus exerts no force onthe piston which tends to counteract the upwardly acting force exertedby the liquid on the lower side of the piston.

Once the tool is in position in the bottom of the well bore asillustrated in FIGURE 1, the upwardly acting bottom hole pressure hasovercome the downward bias of the compression spring 132, and has forcedthe piston body 110 upwardly until the valve closure member 96 engagesthe frusto-conical tapered aperture 52 through the seat 48 and closesthis aperture. At this time, no liquid can flow via the opening 58through the aperture 52 and upwardly into the tubing string. Flow of theliquid into the tubing string, which is open to the atmosphere at thetop, can occur, however, through the capillary orifice 4i). The liquidthus gradually builds up in the tubing string 24 above the valve seat48, being forced through the capillary orifice 40 by the pressure of gasaccumulated in the annulus between the casing 10 and the tubing string.The liquid continues to rise in the tubing string 24 and simultaneouslywith the introduction of liquid into the tubing string via the capillaryorifice 46, liquid is permitted to pass downwardly through the smalldiameter tubing 109 from the orifice 42 to the aperture 107. Liquid thuscommences to accumulate in the bore of the central body section 34 abovethe sealing ring 112.

As liquid continues to rise in the tubing string 24, the force exertedby the increasing hydrostatic head increases and is transmitted throughthe small diameter tubing 109 into the space within the central tubingsection 34 above! the sealing ring 112. In the hypothetical exampleunder discussion, when the hydrostatic head developed by the rise ofliquid in the tubing string 24 reaches a magnitude such that a force of300 p.s.i.g. is exerted on the upper side of the piston (above thesealing ring 112), the combined forces of this hydrostatic head and thedownwardly biasing influence of the spring 132 balance or counteract theupwardly acting bottom hole pressure tending to force the piston bodyupwardly so that the piston is balanced. Further flow of water under thegas pressure existing in the well annulus through the capillary orifice4t] and into the tubing string 24 will thus result in a sufficientdownwardly acting force being developed to cause the piston body 110 toreciprocate downwardly in the body sections 34 and 36 so that the valveclosure member 96 moves off the seat 48, and the tapered aperture 52 isopened. This opening of the valve formed by.the seat 48 and closuremember 96 permits a relatively large volumetric fiow of liquid to occurthrough the opening 58 and thence through the tapered aperture 52 intothe tubing string 24. The result is a rapid decrease in the accumulatedhead of liquid in the annulus surrounding the pro duction tubing string24 and soon the level of the water in this annulus reaches thehorizontal level of the capillary orifice 46. As the water moves belowthis level, the gas accumulated in the annulus is free to pass throughthe capillary orifice 40 and into the bore of the tubing string 24. Theinrush of gas then forms a pneumatic piston under the head of wateraccumulated in the tubing string 24 with the result that this water israpidly blown or lifted to the surface through the tubing string 24 andis discharged through the pipe 26. A substantial amount of water is thusunloaded by a relatively small amount of gas and without any significantdecrease in the total gas pressure of the reservoir.

As gas replaces the liquid in the tubing string 24 above the tool 39,the weight of the liquid is replaced by the weight of the gas in thetubing string and consequently no hydrostatic force continues to actdownwardly on the piston body 110 except for the very small amount whichresults from liquid accumulated in the bore of the central body section34 and in the small diameter tubing 109. Thus, the bottom hole pressureagain becomes suificient to close the valve by moving the piston body110 upwardly, and the cycle of operation is ready to be repeated.

At this point, it should be pointed out that the construction of thepiston means used in the invention permits closure of the valve member96 on the seat 48 without chattering or vibration. The smooth seatingaction described is effected by the operation of the small diameterfirst conduit 116 and the air bleed tube 118 which extends from outsidethe piston body 110 to the hollow interior thereof. Thus, during theinflux of water via the capillary orifice 40 into the tubing string 24with the resultant gravitation of water through the small diametertubing 109 into the space above the sealing ring 112, the liquid alsopasses through the conduit 116 and accumulates in the bottom of thehollow interior of the piston body 110. Simultaneously, air containedWithin the hollow interior of the piston body 116 is displaced therefromthrough the air ejection tubing 118 or is at least placed in compressionby the increasing hydrostatic head.

At such time as the gas enters the tubing string through the capillaryorifice 40, and frequently also through the relatively large opening 58,the acting hydrostatic head is suddenly removed by the pneumatic pistonformed by the entering gas with the result that the piston body 1H)suddenly moves upwardly in the tool, and the valve formed by the seat 48and closure member 96 is closed. This upward movement of the piston body110 is opposed by the gas which has been placed in compression by theintroduction of water through the small diameter tubing 1059 into thebore of the central body section 34 in the manner hereinbeforedescribed. This entrapped, compressed gas tends to cushion the seatingstroke of the piston body 110 and the valve stem 94 since the gasbecomes more compressed as the piston body moves upwardly in the borethrough the central body section 34. Once the air bleed tube 118 movesupwardly so that its open upper end is above the level of liquidaccumulated in the bore through the central body section 34, thecompressed air located above this liquid is free to enter this tube withthe result that water accumulated in the bottom of tie hollow interiorof the piston body 110 is forced upwardly through the first conduit 116and can then be ejected under air pressure through the small diametertubing 16? into the space above the valve seat 48. The small diameter ofthe first conduit 116 and the tubing 109 assure that a dashpot actionwill be obtained in the ejection of liquid and air through thesetubings.

At such time during the operation of the tool as water has accumulatedin the tubing string 24 to a height such that the piston body 110 willbe moved downwardly and the valve opened, the movement of the pistonbody tends to enlarge the space existing within the central body section3 above the sealing ring 112 and the result is that a partial vacuum iscreated in the bore of the central body section. This evacuationprovides a pneumatic spring cushioning the downward movement of thepiston body 110 and preventing chattering or bouncing as the downwardlyfacing shoulder 112 contacts the upwardly facing shoulder 128. Gas orliquid to fill the partial vacuum created by this downward movement ofthe piston body 110 must be drawn either from the hollow interior of thepiston body 110, or through the small diameter tubing 109, and sinceboth the conduit 116 and air bleed tube 118 are of relatively smalldiameter, they again provide a dashpot effect preventing rapid fillingof the partial vacuum by liquid or gas drawn from within the hollowinterior of the cylinder of the piston body 110.

After one complete cycle of the tool 30 in which a substantial amount ofaccumulated liquid is unloaded in the manner described, the valveconstituted by the seat 48 and the valve closure member 96 will remainclosed until such time as enough liquid has re-entered the annulus ofthe well to build up a liquid column within the tubing string 24providing sufficient hydrostatic head to again open the valve. When thiscondition has been attained, the valve again opens, permitting rapidinflux of liquid, followed by a charge of gas from the annulussufficient to force the accumulated liquid to the surface.

The provision of the compression spring 132 and the adjusting nut 130permits the tool to be adapted for use under differing well conditionsso that the tool responds to different liquid columns in the tubingstring. The cycle of operation can also be adjusted to any period whichmay be desired by proper sizing of the capillary orifice 40 and therelatively large opening 58. Preferably, the capillary orifice 40 is ofsufiiciently small size that grains of sand or other foreign materialsentrained in the liquid in the well bore will not plug or stop theorifice. As a preferred alternative, a fine mesh screen or wire cloth isplaced across the orifice 40 in an aperture or a recess 140 provided inthe Wall of the upper tubing section 32 and functions to preventdeleterious materials from entering and choking the orifice. Therelatively simple construction of the tool insures a minimum ofmalfunction during its use, and it is characterized in having a long andrelatively trouble-free operating life. The flexible connection affordedby the engagement of the connecting collar 102 with the ribbed lower endof the valve stem 94 and the upwardly projecting piston neck 106 alsoassures that forces of large magnitude which may be imposed on the toolby unanticipated well conditions or improper use will not render thetool inoperative.

As an example of the use of the invention, a non-commercial well, whencompleted, had a potential of 200M cf. of natural gas per day and wasthus considered infeasible to produce. The well was drilled in anextremely tight rock and was acidized during completion stages. When aneffort was made to produce the well, it would load up with liquid andkill the gas volume. The well was tested for two months for itsproduction capabilities. barrels of oil were recovered during thetesting period.

The tool of the present invention was placed in the well for the purposeof unloading the water and oil without exhausting the gas supply. Thebias of the resilient spring was set for 500 p.s.i.g. by adjustment ofthe adjusting nut. An an 8-day shut-in test, 98 barrels of oil wasproduced and 70 barrels of water and over this period, the gas pressurein the annulus dropped from 1550 p.s.i.g. to 1260 p.s.i.g. No gas waspassed through the annulus. Since relatively little liquid was producedon the last two days of the test, it is believed that the toolsuccessfully dried up the area around the well bore. The casing pressurestabilized at 1260 pounds upon completion of the test.

From the foregoing description of the invention, it will have becomeapparent that the present invention provides a highly efiicient anduseful tool for unloading liquid from a gas well in an economical andreliable manner. The tool is ruggedly constructed and is reliable overlong periods of operating life.

Although a specific embodiment of the invention has been hereinillustrated in order to provide an example of the manner in which it isconstructed, it will be readily apparent that various changes andmodifications can be made in the depicted structure without departingfrom the basic principles which underlie the invention. All such changesand modifications are therefore deemed to be circumscribed by the spiritand scope of the present invention except as the same may be necessarilylimited by the appended claims or reasonable equivalents thereof.

What is claimed is:

1. A device for removing liquids from a gas well comprising:

an elongated tubular element having first and second ends, and having abore extending therethrough between the ends, said tubular elementincluding upper, central and lower body sections, said upper bodysection having a capillary orifice extending through the wall thereofinto the bore of said elongated tubular element and having a secondorifice extending through the wall thereof, said upper body sectionfurther having an opening through said wall and spaced along said borefrom said capillary orifice and said second orifice;

an annular seat positioned in the upper body section below saidcapillary orifice and said second orifice and above said opening andhaving a central aperture therethrough;

a valve closure member dimensioned to mate with said seat to preventfiuid flow therethrough;

an elongated valve stem connected at one of its ends to said valveclosure member and extending in the bore of said tubular element;

a piston element secured to the opposite end of said valve stem fromsaid valve closure member and slidingly positioned in the bore of saidtubular element, a portion of said piston element projecting from an endof said tubular element;

plug means sealingly surrounding and slidingly engaging said valve stem,said plug means being positioned in the bore of said tubular element insaid central body portion and obstructing and sealing the bore aroundsaid valve stem;

stop means in said tubular element for limiting the movement of thepiston element, valve stem and valve closure member away from the seat;

adjustable control means located externally of the tubular element andcooperating with the projecting portion of the piston element forresiliently biasing the piston element against the stop means with apredetermined force; and

by-pass conduit means connected to said second orifice, by-passing saidplug means and communicating with the bore through said tubular elementat a point between said piston element and said plug means.

2. A device as defined in claim 1 wherein said piston element includesan elongated, hollow piston body;

a sealing element around said piston body and sealingly engaging theinternal wall of said central body section; and

means for gradually admitting fluid from said bore above said sealingelement into the hollow interior of said piston body.

3. A device as defined in claim 1 wherein said valve closure membercomprises a spherical metallic member.

4. A device as defined in claim 1 wherein said plug means includes asynthetic resin sleeve surrounding and sealingly engaging said valvestem.

5. A device as defined in claim 1 wherein said piston element includesan elongated, hollow piston body having a downwardly facing shoulderformed thereon and positioned in the bore of said tubular element; and

said stop means comprises an upwardly facing shoulder positioned in theline of movement of said downwardly facing shoulder.

6. A device as defined in claim 1 wherein said adjustable control meanscomprises:

an adjusting nut threaded on the portion of said piston element whichprojects from the end of said tubular element; and

a compression spring positioned between said adjusting nut and saidlower body section.

7. A device as defined in claim 1 wherein said central body section hasan opening through the wall thereof into said bore at a point above saidpiston element, and said by-pass conduit means comprises a smalldiameter tubing extending from said second orifice to said lastmentioned opening for conveying fluid from a point in the bore abovesaid valve seat to a point in the bore above said piston element.

8. A device as defined in claim 2 wherein said means for graduallyadmitting fluid comprises:

a first small diameter tubing extending through the wall 10 of saidhollow piston body at a point above said sealing element and terminatingadjacent the lower end of the hollow interior of said piston body; and

a second small diameter tubing extending through the wall of said hollowpiston body at a point above said sealing element and terminating in thehollow interior of said body portion at a point spaced above the lowerend of said first mentioned small diameter tubmg.

9. A device as defined in claim 1 and further characterized to include aflexible connection between said piston element and said elongated valvestem.

10. A device as defined in claim 1 and further characterized to includea hollow cage positioned between and spacing said plug means and saidseat, said cage having a plurality of openings therein in coplanaralignment with said opening through the wall of the upper body section.

11. A device as defined in claim 10 wherein said cage threadedly engagesthe upper end of said plug means, and said seat is pressed into saidcage.

12. A device as defined in claim 11 wherein said piston elementincludes:

an elongated hollow piston body having a downwardly facing shoulderformed thereon;

a sealing element around said piston body and sealingly and slidinglyengaging the internal wall of said central body section;

a first tubing extending through the wall of said hollow piston body ata point above said sealing element and terminating adjacent the lowerend of the hollow interior of said piston body;

a second tubing extending through the wall of said hollow piston body ata point above said sealing element and terminating in the hollowinterior of said body portion at a point spaced above the lower end ofsaid first mentioned tubing;

and wherein said stop means comprises an upwardly facing shoulderpositioned in the line of movement of said downwardly facing shoulder.

References Cited UNITED STATES PATENTS 2,061,289 11/1936 Phipps 1032322,128,475 8/1938 Rodgers 10340 2,192,945 3/1940 Toney 103-232 X2,291,902 8/ 1942 Kelley 103-40 2,356,423 8/1944 OLeary 103-2322,368,999 2/1945 OLeary 103-232 2,865,305 12/ 1958 Vincent 103-2323,075,475 1/ 1963 Otis 103-232 3,212,517 10/1965 Canalizo 103232 ROBERTA. OLEARY, Primary Examiner,

J KRAUSS, Assistant Examiner.

1. A DEVICE FOR REMOVING LIQUIDS FROM A GAS WELL COMPRISING: ANELONGATED TUBULAR ELEMENT HAVING FIRST AND SECOND ENDS, AND HAVING ABORE EXTENDING THERETHROUGH BETWEEN THE ENDS, SAID TUBULAR ELEMENTINCLUDING UPPER, CENTRAL AND LOWER BODY SECTIONS, SAID UPPER BODYSECTION HAVING A CAPILLARY ORIFICE EXTENDING THROUGH THE WALL THEREOFINTO THE BORE OF SAID ELONGATED TUBULAR ELEMENT AND HAVING A SECONDORIFICE EXTENDING THROUGH THE WALL THEREOF, SAID UPPER BODY SECTIONFURTHER HAVING AN OPENING THROUGH SAID WALL AND SPACED ALONG SAID BOREFROM SAID CAPILLARY ORIFICE AND SAID SECOND ORIFICE; AN ANNULAR SEATPOSITIONED IN THE UPPER BODY SECTION BELOW SAID CAPILLARY ORIFICE ANDSAID SECOND ORIFICE AND ABOVE SAID OPENING AND HAVING A CENTRAL APERTURETHERETHROUGH; A VALVE CLOSURE MEMBER DIMENSIONED TO MATE WITH SAID SEATTO PREVENT FLUID FLOW THERETHROUGH; AN ELONGATED VALVE STEM CONNECTED ATONE OF ITS ENDS TO SAID VALVE CLOSURE MEMBER AND EXTENDING IN THE BOREOF SAID TUBULAR ELEMENT; A PISTON ELEMENT SECURED TO THE OPPOSITE END OFSAID VALVE STEM FROM SAID VALVE CLOSURE MEMBER AND SLIDINGLY POSITIONEDIN THE BORE OF SAID TUBULAR ELEMENT, A PORTION OF SAID PISTON ELEMENTPROJECTING FROM AN END OF SAID TUBULAR ELEMENT; PLUG MEANS SEALINGLYSURROUNDING AND SLIDING ENGAGING SAID VALVE STEM, SAID PLUG MEANS BEINGPOSITIONED IN THE BORE OF SAID TUBULAR ELEMENT IN SAID CENTRAL BODYPORTION AND OBSTRUCTING AND SEALING THE BORE AROUND SAID VALVE STEM;STOP MEANS IN SAID TUBULAR ELEMENT FOR LIMITING THE MOVEMENT OF THEPISTON ELEMENT, VALVE STEM AND VALVE CLOSURE MEMBER AWAY FROM THE SEAT;ADJUSTABLE CONTROL MEANS LOCATED EXTERNALLY OF THE TUBULAR ELEMENT ANDCOOPERATING WITH THE PROJECTING PORTION OF THE PISTON ELEMENT FORRESILIENTLY BIASING THE PISTON ELEMENT AGAINST THE STOP MEANS WITH APREDETERMINED FORCE; AND BY-PASS CONDUIT MEANS CONNECTED TO SAID SECONDORIFICE, BY-PASSING SAID PLUG MEANS AND COMMUNICATING WITH THE BORETHROUGH SAID TUBULAR ELEMENT AT A POINT BETWEEN SAID PISTON ELEMENT ANDSAID PLUG MEANS.